X e eugene hebmite



(No Model.)

I E. .HERMITE. r BLEAGHING OF PAPER PULP OR OTHER FIBROUS 0R TEXTILE MATERIALS OR FABRICS.

Patented M u-. 4, 1884. y

lllll'lll'l llllllll I WJ TJ V'EISSES i llni'rnn STATES PATENT OFFICE.

EUGENE HERMITE, or rams, FRANCE.

BLEACHING OF PAPER-PULP OR OTHER FIBROUS OR TEXTILE MATERIALS OR FABRICS.

SPECIFICA'IIO N forming part of Letters Patent No. 294,619, dated March 4, 1884.

Application filed December 3, 1883. (No model.) Patented in France October 22, 15383; in Belgium October 29, 1883; in England October 30, 1883; in Austria-Hungary October 30, 1883; in Spain October 30, 1883; in Russia October 31,1883;- in Germany November 3, 188 3; in Norway November 3, 1883 in Italy November 8. 1883,- in Denmark November 8, 1883; in Sweden November 10, 1883, and in Portugal December 22, 1883.

4 5 cases.

To all whom it may concern:

Be it known that I, EUGENE HERMITE, a citizen of the Republic of France, and residing in Paris, France, have invented certain 5 Improvements in or Connected with the Bleaching of Paper-Pulp or other Fibrous or Textile Materials or Fabrics, of which the following is a specification. v

This process maybe employed for bleaching 1o textile materials generally, but is more especially applicable to bleaching paper-pulp.

' For convenience of description the said pro cess may be considered as divided into two stages.

In carrying out the first stage of the improved process, chloride of sodium or of potassium is decomposed by an electric current, and in presence of a metal, preferably lead, in such a manner as to obtain soda and potash and chloride of lead.

The form and arrangement of the apparatus employed may be modified according to circumstances but good results have been obtained with the apparatus hereinafter de- 2 5 scribed.

The view in the accompanying drawing is a sectional View illustrating the apparatus.

In the center of a wooden vessel, A, the bot tom of which is provided with a discharge- 3Q pipe, a, is placed a porous cylinder, 13, on the axis of which is arranged a leaden cylinder, 0, forming the negative electrode. A second leaden cylinder, D, surrounding the porous cylinder, acts as the positive electrode. Any

5 convenient number of cellsthus constituted are connected in tension.

Underneath the discharge pipes there is provided a wooden gutter or. trough, E,which collects the chloride of lead formed, and con- 0 ducts it to a tank, F, provided for its reception. A- solution of bay salt is prepared in a tank, H, whence it is drawn by a pump, G, and transferred to a store-tank, K, from which it is distributed to the porous vessels and The electric current acts upon the bay salt in the porous vessel, the solution occupying the remaining part of the case, acting more especially as a conducting-liquid. Un- "der the influence of the current chloride of arranged accordingly.

lead is formed at the positive pole, and caustic soda at thehiegative pole, (or potash when chloride'of potassium is used.) The soda is removed by means of pipes Z), extending at one extremity nearly to the bottom of the porous vessels, and connected at the other exu tremity with a closed chamber, L, from which the liquid is drawn by a pump, M, and delivered. into a suitable tank or vessel, N. The soda or potash obtained by this operation is used, in the usual manner for bleaching purposes. The chloride of lead serves to produce the chlorine necessary for bleaching the materials prepared by the soda.

In carrying outthe second stage of the im-- proved process, the chloride of lead obtained by means of the-operation hereinbefore depole, situated above the gauze and insulated therefrom, is constituted by a plate of prepared carbon, platinum,,or platinized copper or other conducting materialproof against the action of chlorine. At the negative pole any suitable conducting material may be employed in place of the lead. The electric current causes'nascent chlorine to be generated at the positive pole, and this chlorine is dissolved in the liquid and bleaches the materials under treatment. At the negative pole is'deposited metallic lead, which may be collected for the market, or is preferably employed for decomposing a fresh quantity of alkaline chloride, as hereinbefore described, being thereby reconverted into chloride of lead, and then again treated as hereinbefore described. Caustic soda (or potash) and chloride of lead are thus obtained by means of the improved process. The soda is used to prepare the textile or fibrous materials in the bleaching process. The gradual and regulated decomposition of the chloride of lead by the electric current in the presence of the fibrous material enables the bleaching to be economically eit'ectcd without injuring the fibers.

For decomposing the chlorides of potassium or of sodium, zinc, iron, or tin may be employed in place of lead at the positive pole. Caustic soda is thereby obtained, as in the first case, and chlorides of zinc, iron, or tin at the positive pole. The chlorides subjected to electrolysis in presence of the textile or fibrous material yield nascent chlorine, and the metal is deposited as hereinbefore described with reference to lead.

I claim 1. In bleaching textile or fibrous materials, decomposing chlorides of soda or potash by an electric current under such conditions as to cause the formation of an alkali (soda or potash) and a metallic chloride, preferably chloride of lead, substantially as hereinbefore described.

2. In bleaching textile or fibrous materials, decomposing the metallic chloride in the presence of the materials that are to be bleached, and recovering the metal in the metallic state for use in subsequent operations, substantially as hereinbefore described.

3. In an apparatus for bleaching fibrous materials, the combination of a rag engine or equivalent apparatus with the above-described devices for simultaneously effecting the electrolysis of the metallic chloride, bleaching the pulp, and recovering'the precipitated metal, substantially as set forth.

In'testimony whereof I have signed my name to this specification in the presence of two subscribing Witncsses.

EUGENE IIERMTTE.

\Vitncsses:

I LEON FRANQKE I,

Ron'r. M. Hoornn. 

